Move hash-test-template's test RNG code and the buffer allocation code
from various test suites into a header test-utils.h. This allows them
to be shared by other test suites.
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://patch.msgid.link/20260802233005.161467-2-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
